Lesbian is a term most widely used in the English language to describe sexual and romantic desire between females. The word may be used as a noun, to refer to women who identify themselves or who are characterized by others as having the primary attribute of female homosexaulity, or as an adjective, to describe characteristics of an object or activity related to female same-sex desire.
Lesbian as a concept, used to differentiate women with a shared sexual orientation, is a 20th-century construct. Although female homosexuality has appeared in many cultures throughout time, not until recently has lesbian described a group of people. In the late 19th century sexologists published their observations on same-sex desire and behavior, and designated lesbians in Western culture as a distinct entity. As a result, women who became aware of their new medical status formed underground subcultures in Europe and North America. Further broadening of the term occurred in the 1970s with the influence of second wave feminism. Historians since have re-examined relationships between women in history, and have questioned what qualifies a woman or a relationship as lesbian. The result of such discussion has introduced three components to identifying lesbians: sexual behavior, sexual desire, or sexual identity.
Men have historically shaped ideas about what is respectable for women in love, sex, and family, and due to the absence of males in a lesbian relationship, frequently rejected the possibility of lesbianism or disregarded it as a valid expression of sexuality. Early sexologists based their characterization of lesbians on their beliefs that women who challenged their strictly prescribed gender roles were mentally ill. Since then, many lesbians have often reacted to their designation as immoral outcasts by constructing a subculture based on gender role rebellion. Lesbianism has sometimes been in vogue throughout history, which affects how lesbians are viewed by others as well as how they view themselves. Some women who engage in homosexual behavior may reject the lesbian identity entirely, refusing to identify themselves as lesbian or bisexual.
The different ways lesbians have been portrayed in the media suggests that Western society at large has been simultaneously intrigued and threatened by women who challenge feminine gender roles, and fascinated and appalled with women who are romantically involved with other women. Women who adopt the lesbian identity, however, share experiences that form an outlook similar to ethnic identity: as homosexuals, they are unified by the discrimination and potential rejection they face from their families, friends, and others. As women, they face concerns separate from men. Lesbians may encounter distinct health concerns. Political conditions and social attitudes also continue to affect the formation of lesbian relationships and families.